Primary producers (organisms that fix CO2 for cellular carbon)
play key roles in both oceanic food chain dynamics and in marine biogeochemistry.
The factors that control their growth directly impact global processes.
Cyanobacteria, including species of Synechococcus, Trichodesmium,
and Crocosphaera, are prominent constituents of the marine biosphere
that account for a significant percentage of global primary productivity.
Additionally, in warm waters diazotrophic cyanobacteria (i.e., Trichodesmium
and Crocosphaera) are vital components of the global nitrogen cycle
through the production of “new” nitrogen. By studying the physiology
of these important microorganisms at the cellular and molecular levels, we
will gain new insights into the factors that affect their growth in situ and
greatly increase our understanding of how marine nutrient cycles impact global
processes.